This invention relates to electrical power management and battery charging. More particularly, it relates to an apparatus and method that allow a battery charger to share the power available from an electrical supply with one or more other pieces of electrically operated equipment, such as an airport passenger bridge, while charging single or multiple batteries.
The airline industry has long employed vehicles around and on airport tarmacs to support airline operations. Until recently, these vehicles, or ground support equipment (GSE), have been predominantly powered by internal combustion engines that burned gasoline or diesel fuel. With the advances in technology related to electrically powered vehicles, such vehicles have become more cost effective to operate and have become more prevalent as ground support equipment. In particular, advances in battery and battery charging technology have made these vehicles more serviceable. Additionally, the improvements in air quality realized by reducing emissions from internal combustion engines have resulted from the increased use of electrically powered ground support equipment.
While the use of electrically powered ground support equipment has reduced the demand for petroleum-based fuels at airport facilities, the demand on the electrical power sources at these facilities has increased. Heretofore, dedicated electrical power supply circuits have been provided for the battery charging required to support electrically powered ground support equipment. Often the power supply must be run considerable distances, and additional electrical distribution centers have been installed to support battery charging at these load centers. This has added significantly to the expense of introducing electrically powered ground support equipment at airports.
We have recognized that one possible approach to mitigating the need to add electrical power capacity at airports is to have the ground support equipment battery charging circuitry share existing electric power with equipment that is used on a low duty cycle basis. One such piece of equipment is a passenger bridge. Airport passenger bridges provide the conduit between airplane and terminal gate for the loading and unloading of passengers. The passenger bridge is powered into position upon aircraft arrival at the gate and is returned to its stored position just prior to aircraft departure. Between uses, there are substantial periods of time during which no power is required by the passenger bridge, but the electrical power source must be capable of providing the power to the bridge when it is called upon to do so.
Sharing electric power between other equipment and battery chargers for ground support equipment, however, presents problems. Some generic load management devices (also called demand management systems) advertise their use with battery chargers. However, their interface with the battery charger is to simply disconnect the electrical supply to the charger. For very simple, low-power chargers this method may provide acceptable results. For large sophisticated battery chargers such as those utilized by electrical powered ground support equipment, however, the charge algorithm that defined the battery charging profile will not appropriately restart from multiple power interruptions likely with generic demand management systems. This renders such systems ineffective for use with ground support equipment.
There is a need, therefore, to effectively and inexpensively supply electrical power to airport ground support equipment battery chargers. It is an object of the present invention to provide such an apparatus and method for doing so.
It is another object of this invention to provide such an apparatus and method that efficiently shares an existing electrical power source between an airport passenger bridge and a battery charger supporting ground support equipment.
It is yet another object of this invention to provide such an apparatus and method that is fully extensible to include two or more airport passenger bridges.
It is still another object of this invention to provide such an apparatus and method that is fully extensible to include two or more battery chargers supporting ground support equipment.
It is yet another object of this invention to provide such an apparatus and method that efficiently shares an existing electrical power source between an AC load and a battery charger.
Additional objects and advantages of the invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations pointed out in the appended claims.